<link rel=stylesheet href='./style.css'>
<script src="./react_17.0.2.js"></script>
<script src="./react-dom_17.0.2.js"></script>

<div id=root></div>

<script>
const e = React.createElement;

function AppHeader(props) {
  return e(React.Fragment, null,
    e('h1', null, `reactjs@${React.version}`),
    e('h3', null, `Reading List: ${props.bookCount}`),
  );
}

class NewBook extends React.Component {
  constructor(props) {
    super(props);
    this.state = '';
  }

  onInput(event) {
    this.state = event.target.value;
  }

  render() {
    return e(React.Fragment, null,
      e('input', {onInput: this.onInput.bind(this)}, null),
      e('button', {
        onClick: () => this.props.onNewBook(this.state),
      }, `new book`),
    );
  }
}

function ColorButton (props) {
  return e('button', {className: props.color, disabled: !props.enabled}, 'button ' + props.nested.index);
}

function ButtonGrid() {
  const buttons = [];
  for (let i = 0; i < 9; ++i) {
    buttons.push(e(ColorButton, {
      color: ['red', 'green', 'blue'][i % 3],
      enabled: i % 2 === 0,
      nested: {
        index: i,
        value: i + 0.1,
      }
    }, null));
  };
  return e(React.Fragment, null, ...buttons);
}

class BookItem extends React.Component {
  render() {
    return e('div', null, this.props.name);
  }
}

class BookList extends React.Component {
  render() {
    return e('ol', null, this.props.books.map(book => e('li', {key: book.name}, e(BookItem, { name: book.name }))));
  }
}

class App extends React.Component {
  constructor(props) {
    super(props);
    this.mountPoint = React.createRef();
    this.state = {
      books: [
        {name: 'Pride and Prejudice' },
        {name: 'To Kill a Mockingbird' },
        {name: 'The Great Gatsby' },
      ],
    };
  }

  render() {
    return e(React.Fragment, null,
      e(AppHeader, {bookCount: this.state.books.length}, null),
      e(NewBook, {onNewBook: bookName => this.onNewBook(bookName)}, null),
      e(BookList, {books: this.state.books}, null),
      e(ButtonGrid, null, null),
      e('div', {ref: this.mountPoint}, null),
    );
  }

  onNewBook(bookName) {
    this.setState({
      books: [...this.state.books, {name: bookName}],
    });
  }
}

window.mountApp = element => ReactDOM.render(e(App, null, null), element);
window.app = window.mountApp(document.getElementById('root'));
window.mountNestedApp = () => window.mountApp(window.app.mountPoint.current);

</script>
